Chapter 13: Adaptive Immune System

These flashcards cover key terms and concepts from the Adaptive Immune System lecture notes, featuring definitions and explanations.

Adaptive Immune System

A specialized immune response that develops specifically against pathogens, involving T cells and B cells.

Lymphoid Cell Lineage

The lineage of cells that gives rise to lymphocytes, including B cells and T cells.

B Cell

develops primary in bone marrow attacks pathogens Outside the cells provides humoral(bodily fluids)immunity

T Cell

develops primarily in the Thymus attacks pathogens inside the cells provides cellular immunity

What do B cells produce and what do they do?

Antibodies that bind to pathogens and neutralize them so they cannot infect new cells, are very specific and will only bind to specific pathogens, neutralized pathogen is “eaten” by innate immune cells

Antibody structure

Comprised of four chains two heavy chains and two light chains

Antibodies are also known as?

Immunoglobulin(Ig)

How do you define the five main isotopes

differences in heavy chain and their function denoted by corresponding Greek letters

IgG

The most abundant immunoglobulin in the serum(80-85%) in internal bodily fluids including blood and lymph, small and flexible for easier access to pathogens of extra cellular spaces of damaged and infected areas, only Ig that can cross placenta provides protection against bacteria,fungi,viruses,and toxins

IgM

The first antibody produced during an immune response makes up 5-10% of serum antibodies, it is largest Ig and provides defense against bacterial infections.

IgA

An immunoglobulin found in mucosal areas, such as tears, saliva, and milk is 5-15% of serum antibodies(second most abundant) neutralizes pathogens protects babies and adults from bacteria, fungi, viruses and toxins

IgE

The least abundant immunoglobulin (less then 1%) involved in initiating allergic reactions and defense against parasites.

IgD

An immunoglobulin less than 1% of blood serum with a role in activating basophils and mast cells, function also signaling and antibody production

RhD in mothers causes?

RhD+ fetuses have Hemolytic anemia exposed to fetal erythrocytes and make RhD specific antibodies that pass to the fetal circulation and cause fetal erythrocytes to be destroyed

Healthy baby

Antibodies produces in primary responses are mainly IgM which does not cross placenta small amounts of low affinity IgG produce cause only minor damage to fetal erythrocytes

Baby born with hemolytic anemia

Large amounts of anti-RhD IgG produced, IgG actively transported from material to the fetal circulation causes massive destruction of fetal erythrocytes

How can hemolytic anemia be prevented

Mother passively infused with anti-RhD antibodies called RhoGAM during pregnancy

How RhoGAM works

Prevents Rh- negative expectant mothers from making antibodies during pregnancy, immune complex’s of fetal erythrocytes coated with IgG to prevent the mother from making a primary B cell response against the RhD antigen

Two classes of T cells that interact with pathogens (classified?)

Cytotoxic T cells and Helper T cells, that are easily distinguishable by specific proteins in there surface

CD

Cluster of differentiation

Cytotoxic T cells express what protein?

protein CD8

Helper T cells express what protein?

Protein CD4

Main function of cytotoxic CD8 T cells

To kill cancer cells and cells that are infected with an intercellular pathogen (ex,virus)

Cytotoxic death facilitated by?

Injecting granzyme(causes cell death) and perforin(pokes holes in cell membrane) into the infected cell leading to apoptosis

Helper T cells function

“Help” other immune cells destroy pathogens, facilitate macrophage activation improving their capacity to phagocytoses extra cellular pathogens,

Helper T cells working with B cells

Stimulate B cells to produce antibodies that bind to extra cellular bacteria and viruses to ensure their elimination

HIV and how it works

Human immunodeficiency virus which causes acquired immunodeficiency syndrome(AIDS) selectively infects CD4 T cells by using the CD4 molecule as its receptor

HIV process in body

Binding to CD4 on a T cell surface the virus gains entry to the cell where it replicates as HIV infection progresses the number of circulating CD4 T cells gradually declines

HIV without treatment

CD4 T cell count will drop to a level at which the adaptive immune response to other types of infection becomes fatally compromised